Chaeles e



(No Model.)

C. E. SCRIBNER.

ELECTRICAL SWITCH BOARD.

No. 254,389. Patented Feb. 2.8.1882.

UNITED STATES PATENT OEEICE.

CHARLES E. SCEIENEE, OE CHICAGO, ILLINOIS, ASSIGNOE TOTHE WESTERNELECTRIC MANUFACTURING COMPANY, OE SAME PLACE.

ELECTRICAL SWITCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 254,389, dated February28, 1882,

i Application tiled December 22, 1881. (No model.)

To all whom it may concern: Be it known that I, CHARLES E. SCRIBNEE, ofChicago, Illinois, have discovered a certain new and usefulImprovementin Switch-Boards, of which the following is a full, clear,concise,

and exact description.

My invention relates to that class of switchboards in which horizontalStrips and vertical rods or bars are used in colnbination with plugs toor pegs for making the connections.

As used at the central oce ot' a telephoneexchange each vertical rodshould be connected to ground through an annunciator, and the currentsent 'from any given station passes from the rod belonging to the lineofthe station through the annunciator of the rod and to ground. K

Heretofore, in order to answer the call, it has been necessary to firstremove the ground- 2o peg and then insert the peg, so as to connect vthebar with the strip to which the signalingbattery is connected. After theorder from the subscriber has been received in the usual manner the plugmust be again removed and z5 inserted, so as to connect the rod with afreeA strip, with which connection is made with the rod of thesubscriber called for.

My improvement consists in pivoting the.

rods so that they may be connected or disconnected from the ground ofthe annunciator or battery, as the case may be, by simply turning therods.

ln the drawings, Figure l is a front elevation of a portion of aswitch-board embodying 3.5 my invention. Three rods, a b c, are shown,each in -a di'erent position from the other two. The horizontal strips defare arranged in the usual manner.

Fig. 2 is a plan showing the connections of the annunciators and thebattery with the rods. Armsg h i are attached to the rods. When rod a isin the position shown its arm g is in Contact with point k of theground-line, in

which is included the coils of the electro-mag- 45 net of theannunciator Z. All rods are thus connected to ground except when inactive use,

and a subscriber, by sending a current to line, operates the annunciatorof his line, thus informing the central oftice of his call. Theattendant, on seeing an annunciator fall, inserts a peg in a hole of therod opposite any free strip, and, using the peg as a lever, turns therod so as to break Contact with the annunciator and connect with thebattery. The arm h of rod b is shown thus connected with contactpoint aof the battery. The callof a subscriber is thus answered, and theoperator at once turns the rod back so as to disconnect from thebattery, but not far enough to connect with the annunciator, and theninserts the peg, so as to connect with the free strip. The peg is shownthus inserted, connecting rod aand strip fof Fig. 2. The switchman maythen connect his telephone to the rod, and, having received the order,call up the subscriber asked for by connecting his line with thebattery, as before described. After the called subscriber is thussummoned his rod is turned back and the peg is inserted, so as toconnect his rod with the strip to which the calling subscriber has been7o connected.

I claim-V 1. The combination of movable bars a b c, for the subscriberslines, and transfer-strips d cf, having plugholes at the intersections,con- 75 tact-arms g la t', and two contact-points for each arm, one forclosing the circuit through the annunciator to ground, the other forconnecting with the signalingbattery, Substantially as shown anddescribed.

2. The combination,substantially as herein described, of upright barsintersecting the trausfer-strips,with contact arms, one attached to eachbar, and pegs for connecting the line of' any given bar to atransfer-strip.

CHARLES E. SCRIBNER.

